With reference to FIG. 1, a prior art engine assembly 2 is shown including two or more housings, such as a cylinder block 4 and a cylinder head 6. The engine housings are typically coupled together using one or more fasteners, such as cylinder head bolts (not shown) and one or more dowels 8, which provided alignment features for locating the cylinder block and cylinder head relative to one another before the fasteners are installed. As depicted, the dowel 8 is typically received within bores formed in the cylinder block and cylinder head that are aligned, e.g., axially aligned, when the engine housings are correctly located relative to one another.
The engine assembly 2 further includes a sump pan 10 configured to form a reservoir 11 for engine oil to be stored in when it is not being circulated around the engine assembly 2. In use, engine oil is pumped from the reservoir 11 in the sump pan 10 into a first oil gallery 12, formed in the cylinder block 4. Oil from the first oil gallery 12 is distributed to the oil consuming components associated with the cylinder block 4 of the engine assembly 2.
A second oil gallery 14 is formed in the cylinder head 6 to distribute oil to the oil consuming components associated with the cylinder head. An oil passage 16 extends from the first oil gallery 12 to the second oil gallery 14 to provide a supply of oil to the second oil gallery. As depicted, the oil passage 16 extends across the joint between the engine housings 4, 6, and hence, a seal, such as a gasket 18, is typically provided between the engine housings around the oil passage 16 to seal the oil passage at the joint between engine housings 4, 6. An oil restrictor 20 may be provided within the oil passage 16. The restrictor comprises an orifice 20a providing a flow area of a predetermine size, which limits the flow rate of oil through the oil passage 16. The oil restrictor 20 is typically installed into the oil passage 16 by push fitting the restrictor 20 into the oil passage 16 where it is retained by a virtue of an interference fit between the oil restrictor 20 and the oil passage. The inventors have recognized several drawbacks with the prior art engine assembly 2 shown in FIG. 1. For instance, during engine assembly the interaction between the oil restrictor 20 and the oil passage 16 may create debris (e.g., chips, swarf, etc.). The debris, for example, may be created when the restrictor is inserted into the oil passage due to the interference fit between the passage and the restrictor and the rotation between the components. Debris in the lubrication system can lead to unwanted wear of lubricated components downstream of the restrictor. As a result, the longevity of the engine is decreased.
In one example, the issues described above may be addressed by an engine assembly including a first housing defining a first oil gallery and a second housing defining a second oil gallery. The engine assembly further includes an alignment dowel configured to be received within the first and second housings to provide an alignment feature for locating a first and second housings of an engine assembly relative to one another. The alignment dowel includes an oil receiving groove formed in an outer surface of the alignment dowel configured to receive oil from the first oil gallery. Additionally, the alignment dowel is configured to provide a flow channel for the oil received in the oil receiving groove to flow to the second oil gallery, the oil receiving groove extends across the outer surface of the alignment dowel, and a centerline of the oil receiving groove extends in a direction with a component in a circumferential direction of the alignment dowel. Providing an alignment dowel with the oil receiving groove allows a constriction to be formed at the intersection between the oil galleries. Consequently, a desired oil flow pattern can be generated in the engine assembly that improves engine lubrication. Moreover, circumferentially positioning the oil receiving groove enables the dowel to be installed in multiple orientations which allow the dowel to provide a desired oil flow pattern in the engine assembly. For instance, in one example, the dowel's radial and/or longitudinal orientation may not be taken into account when the dowel is installed in the oil galleries. As a result, engine manufacturing efficiency is increased.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
To avoid unnecessary duplication of effort and repetition of text in the specification, certain features are described in relation to only one or several aspects or embodiments of the invention. However, it is to be understood that, where it is technically possible, features described in relation to any aspect or embodiment of the invention may also be used with any other aspect or embodiment of the invention.
FIGS. 3, 4, 5, and 7 are shown approximately to scale. However, other relative dimension may be used, if desired.